Simanihot: A Process-Based Model for Simulating Growth, Development and Productivity of Cassava

Abstract

ABSTRACT:The objective of this study was to propose a model, named Simanihot, for simulating growth, development and yield of tuberous roots in cassava, with a choice of two soil water balance models. The model works on a day time step and is calibrated for five cassava cultivars (Fepagro -RS 14, Estrangeira, Cascuda, São José e Paraguaia), with different branching habits and different purpose of use (pasture, food and industry). The model has a graphical interface, where the user can choose one out of two soil water balance models, depending upon the number of known soil variables and details the user wants to know about soil water content.

Modeling growth, development and yield of cassava: A review

“… Tironi et al (2017a) modified the original SIMANIHOT model ( Gabriel et al, 2014 ) and added two soil water balance methods including the Thornthwaite and Mather (1955) approach, and Ritchie (1998) model. The model has 26 crop parameters that include the maximum water uptake by the roots, developmental time to emergence, branching, and beginning of starch accumulation, number of branches, specific leaf area, leaf size, maximum crop growth rate, leaf duration, senescence sensitivity, leaf appearance rate, and stem/shoot ratio.…”

“…The model has 26 crop parameters that include the maximum water uptake by the roots, developmental time to emergence, branching, and beginning of starch accumulation, number of branches, specific leaf area, leaf size, maximum crop growth rate, leaf duration, senescence sensitivity, leaf appearance rate, and stem/shoot ratio. The soil parameters for the Tironi et al (2017a) model are the soil water content at 650 kPa and at field capacity. The leaf appearance rate, leaf area, leaf size and crop growth rate are reduced when a minimum threshold value of the fraction of available soil water is reached based on the soil water balance methods.…”

“…Santhosh Mithra et al (2013) reduce the fibrous root growth when the storage roots initiate growth and terminate stem growth at a specific crop age. It is unclear based on the literature if the maturity stage of the SIMANIHOT model ( Gabriel et al, 2014 ; Tironi et al, 2017a ) was modified from the original GUMCAS model.…”

Observed and estimated leaf appearance of landrace and improved maize cultivars

“…For gladiolus plants, the WE is part of the PhenoGlad model with an error of 0.5 leaf (UHLMANN et al, 2017). Another example is for cassava plants in which the WE was included in the Simanihot model with a mean error of 6.76 leaves (TIRONI et al, 2017). After calibrated and tested for maize cultivars with a broad genetic variability, the WE may represent an important tool.…”

Application of Mathematical Epidemiology to Crop Vector-Borne Diseases: The Cassava Mosaic Virus Disease Case

“…It is a positive increasing function of the biomass [31]. According to [29], where the authors fit cassava (dry) biomass growth with a logistic equation, we set m h (P) = m h P. Our crop growth model is very "simple" compared to previous process-based models (PBM) (like for instance GUMCAS [37], GUMCAS-DSSAT [19], and SIMANIHOT [42]), but sufficient to explore the dynamics of the disease, while keeping the model mathematically tractable. Last but not least, the use of the previous PBM needs to estimate all the physiological parameters not only on healthy plants but also on diseased plants.…”